1. Field of Invention
The invention relates to concrete placing machinery. More particularly, this invention relates to a shield for controlling rebound of hydrated concrete during placing of such hydrated concrete using a feed hose and pump system.
2. Description of the Related Art
Feed hoses used in conjunction with concrete pumping systems are known in the art. Such feed hoses are arranged, for example, on the concrete distributor mast of a stationary or mobile concrete pump. In fabricating a concrete structure, a form is prepared to hold a measure of hydrated concrete. A feed hose coupled to a distributor mast is then configured to hang above the form and carry hydrated concrete from a concrete pump interior into the form. Upon placement of the hydrated concrete into the form and surface finishing of the hydrated concrete, the concrete is thereafter allowed to harden and cure to form a concrete structure.
In placing concrete within a large form, such as a form for a floor or deck structure, it is often necessary to manipulate the feed hose and move the feed hose over different parts of the form in order to place hydrated concrete in different parts of the form. Such manipulation of the feed hose allows the user to distribute hydrated concrete, for example, over a large area, and to prevent excessive piling of hydrated concrete. Although many concrete pumps incorporate a mechanically repositionable distributor mast to accomplish major repositioning of the feed hose, precise manipulation of the feed hose over different parts of the form is typically accomplished through gripping the feed hose near the outlet and manipulating the feed hose by hand. Such hand manipulation of the feed hose requires a person to stand near the form and hold the feed hose outlet over the desired portion of the form.
Among the typical components of hydrated concrete are coarse aggregates such as rock or gravel, fine aggregates such as sand or grit, and hydrated cement. Due to the collective weight of these components, relatively high forces are typically required to pump hydrated concrete into a form. Moreover, the physical properties of hydrated concrete make hydrated concrete prone to splatter and rebound upon impacting a surface. Thus, while pumping hydrated concrete into a form, the hydrated concrete often impacts the form. The result is often splattering and rebound of the hydrated concrete onto the area surrounding the form.
Rebound of hydrated cement and fine aggregates can result in messing of the area surrounding the form, as well as messing of the user manipulating the feed hose. Rebounding coarse aggregates often impact the area surrounding the impact site, which can be annoying as well as dangerous. Rebounding coarse and fine aggregates, such as rocks and sand, found in hydrated concrete can foul and damage property and injure users and other bystanders. Furthermore, hydrated cement is a strong base and often irritates the skin and eyes under conditions of prolonged exposure. It is therefore desirable to provide an apparatus for limiting rebound of hydrated concrete as such hydrated concrete is placed through the outlet of a feed hose.